Electric seam-welding.



a. THOMSON. ELECTRIC SEAM WELDING.

- APPLICATION FILED MAY 10', 1913,

Patented Jn. 13,1914;

W 1 JHHEMM QI H H 1* @W'Hi U I H 1 1 HI I 1 ML HHWIW Hi- WW I 1W HI i 2#20 TANOVE/AQZFO/V 'WC I ATTORNEKS UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO THOMSONELECTRIC WELDING COMPANY, OF LYNN, MASSACHUSETTS, A CORPORA- TION OFMASSACHUSETTS.

ELECTRIC SEAM-VVELDING.

To all whom it may concern:

Be it known that I, Eunu Tnonson, a citizen of the United States, and aresident of Swampscott, in the county of Essex and State ofMassachusetts, have invented certain new and useful Improvements inElectric Seam-VVelding, of which the following is a specification.

My invention relates to methods of male somewhat difficult to produce,and the metal will have lost more or less of its flat condition at theseam. This is due to the crowding down of the metal, and its lateraldisplacement. i

The object of my invention is to avoid failure of making a proper seamdue to this Warping-or buckling.

According to my invention the seam is first spot welded in a number ofseparated spots suflicient-in number and nearness to one another to holdthe parts securely in place for the final continuous weld, the spotwelding being done with the plates or sheets in their proper position.This spot welding I will not throw them out of position. Then,

the seam having been, as it were, started in Specification of LettersPatent.

Application filed May 10, 1913. Serial No. 766,729.

Patented Jan. 13, 1914.

this way, the whole seam starting fromany point is made by putting thework between the welding rollers and uniting the sheets or platesthroughout the whole extentof their nteeting to form the continuous seamdesired. The spot welding prevents any dis placement of the sheets oneover the other during the final process, and therefore renders possiblethe making of a good ob where otherwise it would be difficult.

The accompanying drawings illustrate in purely diagrammatic fashion thesteps of theprocess.

Figure 1 shows the first stage of the proccated by numerals l, 1, theextent of the overlap by the distance between the dotted line 2 and thecontinuous line 3 forming the edge of the upper sheet and the spotsbeing indicated at the points 6t.

The second stage of the process is indicated by the F ig. 2, acontinuous seam being merely indicated by the continuous line 5.

What I claim as my invention is The herelndescrlbed improvement inmaking continuous seams 111 sheet metal by the electric welding process,consisting in first forming a number of welds at spots along the line ofthe proposed seam and then forming a continuousseam by the electricwelding process along the line of said spots.

Signed at Lynn in the county of Essex and State of Massachusetts this2nd. day of May A. D. 1913.

ELIHU THOMSON. Witnesses:

JOHN A. MoMAwUs, J12, Hnnnr A. ANDnRsnN.

ess, the two overlapped sheets being indi-

